Outlet box



I Aug. 9 .1927.

C. RENSHAW OUTLET BOX Filed Feb. 16. 1925 FIEL'I.

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Execafru. .Y

Patented Aug. V9, 1927.

,UNITED' .STATES 1,638,510 PATENT OFFICE.

CLARENCE BENSHAW, DECEASED, LATE OF FITTSBURGH, PENNSYLVANIA, BY MAIDEE IB. RENSHAW, EXECUTE/IX, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO NA- TIONAL METAL MOLDING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A COR- PORATIONIOF PENNSYLVANIA.

OUTLET BOX.

Application filed February 16, 1925 Serial No. 9,560.

It is the object of the invention to provide an outlet box of the class sometimes designated as'cable boxes or plates, for use in making connections with electrical conductors enclosedfin flexible cables, either armored cables or those having a non-metallic sheath, which will be of simple and easilyapplied construction, and which can-be made economically of pressed or stamped sheet metal, as distinguished from the cast metal boxes now more commonly used.

In the accompanying drawings there is shown sufficiently for purposes of illustration a box embodying the invention in its preferred form. Figure 1 is a plan view of the open body portion of the box. Figure 2 is a plan view of one of the bushing brackets or shelves, and Figure 3 is a view in cross-section on the line TIL-III of Figutc 2. Figure 4 is a top plan View of one of the clamping-members, and Figure 5 is a view in cross-section on the line 'V-V of Figure 1.- Fi-gure 6 is a view in cross-section on the line Vl-JTI ofFigure 1, showing an r 'armored cable secured inv the box.

The body of the box comprises a base or floor 1 having an outwardly-projecting sidewall 9, and a central projecting stud 3, all preferably stamped or drawn from a single piece of sheet metal. The floor 1 is provided with openings 4: for the introduction of the cables, originally closed bythe usual knock- 0uts5. Securance holes 6 for nails or. screws are also provided in the floor. The stud 3 is here shown as hollow and externally threaded for the attachment of an electric.

fixture. If, as is sometimes, the case, at-

tachment is to be made to a gas-pipe, the

form of the stud will be'correspondingly' altered. It is preferred, as shown, that the stud 3 shall be of less height (or depth) than the wall 2, and it is of advantage 1n the form of box body shown, that the space between the stud andthe walliisjopen and unobstructed, so that the stud can be threaded without difficulty.

-Bushings 7 for the conductors are pro-- vided, which are shown as formed in brack-.

- ets or shelves 8 secured to the wall 2 above and in line with the cable openings l in the floor .1. One of these brackets is shown in 9, the latter being passed through slots 10 in the wall 2 and bent over upon the outer face of the wall'to secure the bracket firmly in place. The bushing openings 7 drifted in the bracket, and'the edge of the metal forming'gthe opening is curled and preferably beaded as shown at 11 in Figure 3. This is preferable when armored cable is being used, the armor being cut away below the bracket and the beaded edge 11 of the opening serving to protect the bare insula tion of the conductors from injury by contact with the sharp edge ofthe armor. The bushing brackets 8 are preferably placed a suflicient distance below the open edge of the wall 2 to permit the conductors to'be bent over so as not to project above the edge, and in many cases there willthus-be provided within the box body sufficient room for the necessary splices and connections. This permits the useof a fiat closure or a fixture having a flat inner surface. Threaded holes, as 12, may be formed in the brackets 8 to receive the-threaded shanks of attaching screws for the closure.

For securing the cable or cables in place in the box adjustable clamping-members are between the respective brackets 8 and the floor of the box. The preferred form of clamping-member, which is believed to be new per se as well as in the described combination, is shown in Figures 4:, 5 and 6. It consists of a channel section 13, the opposite. horizontally arranged flanges or win-gs 14 of which are provided with vertically aligned notches 15 adapted to engage the cable, and having a threaded hole 16 in its web 17' to receive the threaded shank of an adjusting screw 18 projected through the side wall of. the box and operated from the outside,,t-he hole 16 being preferably drifted as shown. The adjusting screw 18, which preferably has a fiat-surfaced head,

I is inserted thrbugh the hole 19' in the wall 2 and its inner threaded portion is caused to engage the thread in the'hole 16 in the web of the clamping-member. Then by turning the screw the clamping-member will be drawn outwardly, and the edges of the are vertically aligned notches 15 will be caused to engage the surface of the cable and bind a it firmly against the inner face of the wall Figure 2 in the form of a plate having two. gbushing openings and provided .with' lugs V and while withsuch a box 2 as well as the edge of the knockout open-v in 4 in the floor 1. The clamping-member 13 y reason of its channeled form has a high tensile strength to resist horizontal strain, while at the same time its opposite'wings 14 may take a slight ficxure so that the edges of the notches 15 will engage in the grooves in the surface of the helically coiled armor when flexible armored cable is used.

The body of the box herein described ma of course be a casting, but, as alre'ad state it is preferred to make it' of Wrong t metal such as pressed and drawn sheet steel. Heretofore attempts to make Wrought metal outlet boxes of the present type have not met with any notable degree of commercial success, and their commercial been confined mainly to castmgs. The box body of this inventlon is of a form, which can be roduced economically by pressing,

body the accesproduction has sory parts may bevaried without departure from the invention, tion substantiall a's herein shown and described is-novel in structure, neat and compact, Sandmay be readilyjins'talled under normal conditions of-use' The invention is claimed as .follows:

In an outlet box having an o ening for the admission of an electric cab e, a. cable clamping member of 'channeled cross sectional form havina web portion jecting parallel wing portions being adapted to bear against the surface of the cable, and means projecting through the wall of the box and connected to said web portion for adjusting the clamping-member.

In testimony whereof I have hereunto set my hand.

, I MAIDEE B. RENSHAW, Easeoutm'a: of Clarence Remhww, Deceased.

the complete combinaand pro- 

